Recording Simulation of Patterned Media Toward 2 Tb/in$^{2}$

Abstract

Recording simulation of bit patterned media for recording densities toward 2 Tb/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> was studied. The magnetic dot was modeled as 10 nm long, 15 nm wide, and 5 nm thick with m <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> =1000 emu/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The dots were arranged in densities of 1-2 Tb/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> on a soft magnetic underlayer with a 25-nm cross track pitch. A head field of a shielded planar head with a pole size of 14times45 nm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and a head-medium spacing of 6 nm was used. When the switching timing of the head field was properly chosen, a 2 Tb/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> pattern was successfully recorded on a track but the obtained switching window was only 2.5 nm due to increased magnetostatic interaction between the dots. Introduction of the exchange coupling between the neighboring dots by connecting the dots was found to increase the switching window up to 6 nm along with an increase in cross track shift margin